A new VPC needs a block and, so you can find it again, a Name tag.

Creating it

VPC=$(aws ec2 create-vpc --cidr-block 10.0.0.0/16 --tag-specifications 'ResourceType=vpc,Tags=[{Key=Name,Value=market}]' --query Vpc.VpcId --output text)

--tag-specifications works as it did for instances in Chapter 3, with ResourceType=vpc. A create command answers with the thing it made, so --query Vpc.VpcId --output text prints just the new id, and VPC=$(…) keeps it. Every command in this chapter uses $VPC.

A larger block than /16 (a smaller number after the slash, such as /8) fails with InvalidVpc.Range.

What comes with it

No subnets yet, and no way in or out: a VPC starts sealed. The next lessons add the pieces.

DNS hostnames

aws ec2 modify-vpc-attribute --vpc-id $VPC --enable-dns-hostnames

This gives instances with a public IP a public name as well, such as ec2-54-23-117-9.compute-1.amazonaws.com. The default VPC has it on; a new VPC does not.

Finding it again

A variable lasts only as long as the shell. In a new terminal, find the VPC by its Name tag:

VPC=$(aws ec2 describe-vpcs --filters Name=tag:Name,Values=market --query "Vpcs[0].VpcId" --output text)